1. Field of the Invention
The subject invention generally pertains to attaching handles to tools, and more specifically to attaching handles to tools using an eye and wedges.
2. Description of Related Art
Currently handles are secured to tools with a variety of methods.
(1) One method utilizes an eye in the tool that is tapered larger from the center of the eye toward both open ends of the eye, such as striking tools and the like, and a handle whose geometry matches the entrances taper of the eye. The handle is driven into the entrance end of the eye, and wedges are driven into the protruding end of the handle. These wedges expand the end of the handle to conform to the taper of the eye, trapping the handle in the eye.
(2) An improvement on method 1, utilizes the same type of tapered eye and handle. A ferrule is riveted to the bottom of the head; this ferrule bears against wedge shaped handle clamps, which bear against a taper on the handle. See U.S. Pat. No. 1,115,637.
(3) Another method uses an eye with the exit end of the eye smaller than the entrance end of the eye, and a handle that is of matching taper, such as a pickax and the like. The handle is inserted butt-end first into the entrance end of the eye and travels through the eye until the handle wedges tightly into the eye.
(4) An improvement on method 3, utilizes the same type of tapered eye and handle; `J` bolts and a cross bar are used to secure the handle in the tool on a more permanent basis. See U.S. Pat. No. 4,669,342.
(5) Another method uses a tapered eye which has an exit end smaller than the entrance end of the eye, a handle with an assembly end that matches that taper, and has two through holes longitudinal with that taper; and a plate larger than the exit end of the eye with two through holes that mate to the through holes in the handle taper. The assembly end of the handle is inserted into the eye; the plate is placed over the exit end of the eye. The tool and handle are held together by passing long screws through the holes in the plate and the holes in the tapered end of the handle, and securing with nuts and lockwasheres that bear against shoulders on the exposed handle taper. See U.S. Pat. No. 4,096,895.
(6) Other systems use a ferrule over the hollowed out attaching end of the handle, such as pitchforks and hoes and the like. The shank of the tool is pressed into the end of the ferrule covered handle, expanding the handle to fit the ferrule.
(7) Some systems use chemical epoxies to assemble handles to tools, such as striking tools and the like.
(8) Some handles are mechanically forced into a hole in the tool then soldered, such as striking tools and the like.
(9) Some tools have an integral ferrule, such as shovels and the like. The handle is inserted into the ferrule, and the two are cross-riveted together.
(10) Some methods use a form of threaded fastener between the end of the handle and the eye of the tool, such as sweeping tools and the like.
(11) Some methods use a combination of the methods mentioned.
The disadvantages of method 1: the wedges work loose due to stress on the handle; the wedges work loose due to changes in the size of the handle because of moisture content or temperature variations; once the wedges work loose they tend to work loose easier the next time; additional wedges may be inserted to tighten the assembly but they must be either kept on hand for insertion or procured as needed; inserting additional wedges into the handle is only a temporary fix, eventually the handle becomes damaged enough to be unsafe and must be replaced; replacing a handle due to breakage, or for safety reasons, is difficult because wedges are meant to go in, not out, and cannot be easily removed; the end of the handle cannot be readily removed from the tool because the handle is larger on either end of the eye and smaller in the center of the eye. To remove a handle of this sort from the tool requires several different additional repair type tools and nearly an hour of time.
The disadvantages of method 2: identical to the the disadvantages of the first. The advantage that the second method offers is preventing the tool from coming off inadvertently. Tightening the attachment is accomplished with wedges similar to method 1.
The disadvantage of method 3: during use the tool must be continually checked to ensure that is secure. The tool can become loose at the most inopportune time and injure the hand, arm, or head of the user.
The disadvantage of method 4: the `J` bolts protrude beyond the head of the tool where, unbeknownst to the user, they may shear off during normal use; in which case the tool reverts to method 2.
The disadvantages of method 5: the plate over the exit end of the eye could be sheared off during normal use, and the tool would immediately become separated from the handle creating a safety hazard; the design limits the types of materials for the handle due to the stresses that the screws induce on the shoulders of the tapered end.
The disadvantage of method 6: the handle can work loose through use or changes in moisture content or temperature variations, causing the handle and tool to separate unexpectedly. Such unexpected separation can cause the user to over exert and strain muscles. Replacing a handle of this sort can be accomplished, but should be done with special tools for best results.
The disadvantages of method 7: epoxies eventually weather and crack to the extent that they loosen or fall out of the eye, and the tool inadvertently comes off. Repairing an attachment of this sort or replacing the handle involves hazardous materials, which require specific and expensive handling and disposal methods.
The disadvantage of method 8: if the handle or tool becomes damaged, the entire tool must be replaced.
The disadvantage of method 9: it is difficult to replace the old handle without several different tools.
The disadvantages of method 10: one or both members of the threaded type fastener is made of wood, such threaded fasteners are not as durable as the tool or the handle in which they are placed; damage to the threads on either the handle or tool requires replacing the damaged member; a threaded type of securing method will come undone should the tool need to be rotated with the handle, rotating the assembly in the wrong direction will loosen the connection.
The disadvantage of method 11 are a combination of the disadvantages of whatever methods are involved.